1 | /* vi: set sw=4 ts=4: */
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2 | /*
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3 | * cut.c - minimalist version of cut
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4 | *
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5 | * Copyright (C) 1999,2000,2001 by Lineo, inc.
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6 | * Written by Mark Whitley <markw@codepoet.org>
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7 | * debloated by Bernhard Fischer
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8 | *
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9 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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10 | */
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11 |
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12 | #include "libbb.h"
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13 |
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14 | /* This is a NOEXEC applet. Be very careful! */
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15 |
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16 |
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17 | /* option vars */
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18 | static const char optstring[] ALIGN1 = "b:c:f:d:sn";
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19 | #define CUT_OPT_BYTE_FLGS (1<<0)
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20 | #define CUT_OPT_CHAR_FLGS (1<<1)
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21 | #define CUT_OPT_FIELDS_FLGS (1<<2)
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22 | #define CUT_OPT_DELIM_FLGS (1<<3)
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23 | #define CUT_OPT_SUPPRESS_FLGS (1<<4)
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24 |
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25 | static char delim = '\t'; /* delimiter, default is tab */
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26 |
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27 | struct cut_list {
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28 | int startpos;
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29 | int endpos;
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30 | };
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31 |
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32 | enum {
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33 | BOL = 0,
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34 | EOL = INT_MAX,
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35 | NON_RANGE = -1
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36 | };
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37 |
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38 | /* growable array holding a series of lists */
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39 | static struct cut_list *cut_lists;
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40 | static unsigned int nlists; /* number of elements in above list */
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41 |
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42 |
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43 | static int cmpfunc(const void *a, const void *b)
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44 | {
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45 | return (((struct cut_list *) a)->startpos -
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46 | ((struct cut_list *) b)->startpos);
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47 |
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48 | }
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49 |
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50 | static void cut_file(FILE * file)
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51 | {
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52 | char *line = NULL;
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53 | unsigned int linenum = 0; /* keep these zero-based to be consistent */
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54 |
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55 | /* go through every line in the file */
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56 | while ((line = xmalloc_getline(file)) != NULL) {
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57 |
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58 | /* set up a list so we can keep track of what's been printed */
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59 | char * printed = xzalloc(strlen(line) * sizeof(char));
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60 | char * orig_line = line;
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61 | unsigned int cl_pos = 0;
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62 | int spos;
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63 |
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64 | /* cut based on chars/bytes XXX: only works when sizeof(char) == byte */
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65 | if (option_mask32 & (CUT_OPT_CHAR_FLGS | CUT_OPT_BYTE_FLGS)) {
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66 | /* print the chars specified in each cut list */
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67 | for (; cl_pos < nlists; cl_pos++) {
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68 | spos = cut_lists[cl_pos].startpos;
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69 | while (spos < strlen(line)) {
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70 | if (!printed[spos]) {
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71 | printed[spos] = 'X';
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72 | putchar(line[spos]);
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73 | }
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74 | spos++;
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75 | if (spos > cut_lists[cl_pos].endpos
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76 | || cut_lists[cl_pos].endpos == NON_RANGE)
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77 | break;
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78 | }
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79 | }
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80 | } else if (delim == '\n') { /* cut by lines */
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81 | spos = cut_lists[cl_pos].startpos;
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82 |
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83 | /* get out if we have no more lists to process or if the lines
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84 | * are lower than what we're interested in */
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85 | if (linenum < spos || cl_pos >= nlists)
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86 | goto next_line;
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87 |
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88 | /* if the line we're looking for is lower than the one we were
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89 | * passed, it means we displayed it already, so move on */
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90 | while (spos < linenum) {
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91 | spos++;
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92 | /* go to the next list if we're at the end of this one */
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93 | if (spos > cut_lists[cl_pos].endpos
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94 | || cut_lists[cl_pos].endpos == NON_RANGE) {
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95 | cl_pos++;
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96 | /* get out if there's no more lists to process */
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97 | if (cl_pos >= nlists)
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98 | goto next_line;
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99 | spos = cut_lists[cl_pos].startpos;
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100 | /* get out if the current line is lower than the one
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101 | * we just became interested in */
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102 | if (linenum < spos)
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103 | goto next_line;
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104 | }
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105 | }
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106 |
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107 | /* If we made it here, it means we've found the line we're
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108 | * looking for, so print it */
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109 | puts(line);
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110 | goto next_line;
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111 | } else { /* cut by fields */
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112 | int ndelim = -1; /* zero-based / one-based problem */
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113 | int nfields_printed = 0;
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114 | char *field = NULL;
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115 | const char delimiter[2] = { delim, 0 };
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116 |
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117 | /* does this line contain any delimiters? */
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118 | if (strchr(line, delim) == NULL) {
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119 | if (!(option_mask32 & CUT_OPT_SUPPRESS_FLGS))
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120 | puts(line);
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121 | goto next_line;
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122 | }
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123 |
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124 | /* process each list on this line, for as long as we've got
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125 | * a line to process */
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126 | for (; cl_pos < nlists && line; cl_pos++) {
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127 | spos = cut_lists[cl_pos].startpos;
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128 | do {
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129 | /* find the field we're looking for */
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130 | while (line && ndelim < spos) {
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131 | field = strsep(&line, delimiter);
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132 | ndelim++;
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133 | }
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134 |
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135 | /* we found it, and it hasn't been printed yet */
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136 | if (field && ndelim == spos && !printed[ndelim]) {
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137 | /* if this isn't our first time through, we need to
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138 | * print the delimiter after the last field that was
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139 | * printed */
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140 | if (nfields_printed > 0)
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141 | putchar(delim);
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142 | fputs(field, stdout);
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143 | printed[ndelim] = 'X';
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144 | nfields_printed++; /* shouldn't overflow.. */
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145 | }
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146 |
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147 | spos++;
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148 |
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149 | /* keep going as long as we have a line to work with,
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150 | * this is a list, and we're not at the end of that
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151 | * list */
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152 | } while (spos <= cut_lists[cl_pos].endpos && line
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153 | && cut_lists[cl_pos].endpos != NON_RANGE);
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154 | }
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155 | }
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156 | /* if we printed anything at all, we need to finish it with a
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157 | * newline cuz we were handed a chomped line */
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158 | putchar('\n');
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159 | next_line:
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160 | linenum++;
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161 | free(printed);
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162 | free(orig_line);
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163 | }
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164 | }
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165 |
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166 | static const char _op_on_field[] ALIGN1 = " only when operating on fields";
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167 |
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168 | int cut_main(int argc, char **argv);
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169 | int cut_main(int argc, char **argv)
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170 | {
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171 | char *sopt, *ltok;
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172 |
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173 | opt_complementary = "b--bcf:c--bcf:f--bcf";
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174 | getopt32(argv, optstring, &sopt, &sopt, &sopt, <ok);
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175 | // argc -= optind;
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176 | argv += optind;
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177 | if (!(option_mask32 & (CUT_OPT_BYTE_FLGS | CUT_OPT_CHAR_FLGS | CUT_OPT_FIELDS_FLGS)))
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178 | bb_error_msg_and_die("expected a list of bytes, characters, or fields");
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179 |
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180 | if (option_mask32 & CUT_OPT_DELIM_FLGS) {
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181 | if (strlen(ltok) > 1) {
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182 | bb_error_msg_and_die("the delimiter must be a single character");
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183 | }
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184 | delim = ltok[0];
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185 | }
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186 |
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187 | /* non-field (char or byte) cutting has some special handling */
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188 | if (!(option_mask32 & CUT_OPT_FIELDS_FLGS)) {
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189 | if (option_mask32 & CUT_OPT_SUPPRESS_FLGS) {
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190 | bb_error_msg_and_die
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191 | ("suppressing non-delimited lines makes sense%s",
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192 | _op_on_field);
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193 | }
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194 | if (delim != '\t') {
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195 | bb_error_msg_and_die
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196 | ("a delimiter may be specified%s", _op_on_field);
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197 | }
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198 | }
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199 |
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200 | /*
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201 | * parse list and put values into startpos and endpos.
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202 | * valid list formats: N, N-, N-M, -M
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203 | * more than one list can be separated by commas
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204 | */
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205 | {
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206 | char *ntok;
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207 | int s = 0, e = 0;
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208 |
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209 | /* take apart the lists, one by one (they are separated with commas */
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210 | while ((ltok = strsep(&sopt, ",")) != NULL) {
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211 |
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212 | /* it's actually legal to pass an empty list */
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213 | if (strlen(ltok) == 0)
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214 | continue;
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215 |
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216 | /* get the start pos */
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217 | ntok = strsep(<ok, "-");
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218 | if (ntok == NULL) {
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219 | bb_error_msg
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220 | ("internal error: ntok is null for start pos!?\n");
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221 | } else if (strlen(ntok) == 0) {
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222 | s = BOL;
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223 | } else {
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224 | s = xatoi_u(ntok);
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225 | /* account for the fact that arrays are zero based, while
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226 | * the user expects the first char on the line to be char #1 */
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227 | if (s != 0)
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228 | s--;
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229 | }
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230 |
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231 | /* get the end pos */
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232 | ntok = strsep(<ok, "-");
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233 | if (ntok == NULL) {
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234 | e = NON_RANGE;
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235 | } else if (strlen(ntok) == 0) {
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236 | e = EOL;
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237 | } else {
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238 | e = xatoi_u(ntok);
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239 | /* if the user specified and end position of 0, that means "til the
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240 | * end of the line */
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241 | if (e == 0)
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242 | e = EOL;
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243 | e--; /* again, arrays are zero based, lines are 1 based */
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244 | if (e == s)
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245 | e = NON_RANGE;
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246 | }
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247 |
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248 | /* if there's something left to tokenize, the user passed
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249 | * an invalid list */
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250 | if (ltok)
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251 | bb_error_msg_and_die("invalid byte or field list");
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252 |
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253 | /* add the new list */
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254 | cut_lists = xrealloc(cut_lists, sizeof(struct cut_list) * (++nlists));
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255 | cut_lists[nlists-1].startpos = s;
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256 | cut_lists[nlists-1].endpos = e;
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257 | }
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258 |
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259 | /* make sure we got some cut positions out of all that */
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260 | if (nlists == 0)
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261 | bb_error_msg_and_die("missing list of positions");
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262 |
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263 | /* now that the lists are parsed, we need to sort them to make life
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264 | * easier on us when it comes time to print the chars / fields / lines
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265 | */
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266 | qsort(cut_lists, nlists, sizeof(struct cut_list), cmpfunc);
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267 | }
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268 |
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269 | /* argv[0..argc-1] should be names of file to process. If no
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270 | * files were specified or '-' was specified, take input from stdin.
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271 | * Otherwise, we process all the files specified. */
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272 | if (argv[0] == NULL || LONE_DASH(argv[0])) {
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273 | cut_file(stdin);
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274 | } else {
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275 | FILE *file;
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276 |
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277 | do {
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278 | file = fopen_or_warn(argv[0], "r");
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279 | if (file) {
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280 | cut_file(file);
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281 | fclose(file);
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282 | }
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283 | } while (*++argv);
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284 | }
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285 | if (ENABLE_FEATURE_CLEAN_UP)
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286 | free(cut_lists);
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287 | return EXIT_SUCCESS;
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288 | }
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